Abstract
The effect of thiamine on β-amylase of sweet-potato was studied, and the results obtained are as follows:
1. About 20% inhibition of the activity of β-amylase was caused by the addition of thiamine at the concentration of 10-3M, but no inhibition took place at the concentration of 1/3×10-3M or at less concentration.
2. The activity of β-amylase was not inhibited by pyrimidine derivative and thiazol, or by the mixture of them, but it was inhibited by thiochrome at the concentration equal to that of 10-3M thiamine.
These results seem to suggest that the combination of pyrimidin and thiazol is essential for the inhibition of β-amylase activity by thiamine.
